1// Protocol Buffers - Google's data interchange format
2// Copyright 2008 Google Inc. All rights reserved.
3// https://developers.google.com/protocol-buffers/
4//
5// Redistribution and use in source and binary forms, with or without
6// modification, are permitted provided that the following conditions are
7// met:
8//
9// * Redistributions of source code must retain the above copyright
10// notice, this list of conditions and the following disclaimer.
11// * Redistributions in binary form must reproduce the above
12// copyright notice, this list of conditions and the following disclaimer
13// in the documentation and/or other materials provided with the
14// distribution.
15// * Neither the name of Google Inc. nor the names of its
16// contributors may be used to endorse or promote products derived from
17// this software without specific prior written permission.
18//
19// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30#include <google/protobuf/stubs/stringpiece.h>
31
32#include <string.h>
33#include <algorithm>
34#include <climits>
35#include <string>
36#include <ostream>
37
38#include <google/protobuf/stubs/logging.h>
39
40namespace google {
41namespace protobuf {
42namespace stringpiece_internal {
43
44std::ostream& operator<<(std::ostream& o, StringPiece piece) {
45 o.write(s: piece.data(), n: piece.size());
46 return o;
47}
48
49void StringPiece::LogFatalSizeTooBig(size_t size, const char* details) {
50 GOOGLE_LOG(FATAL) << "size too big: " << size << " details: " << details;
51}
52
53void StringPiece::CopyToString(std::string* target) const {
54 target->assign(s: ptr_, n: length_);
55}
56
57void StringPiece::AppendToString(std::string* target) const {
58 target->append(s: ptr_, n: length_);
59}
60
61bool StringPiece::Consume(StringPiece x) {
62 if (starts_with(x)) {
63 ptr_ += x.length_;
64 length_ -= x.length_;
65 return true;
66 }
67 return false;
68}
69
70bool StringPiece::ConsumeFromEnd(StringPiece x) {
71 if (ends_with(x)) {
72 length_ -= x.length_;
73 return true;
74 }
75 return false;
76}
77
78StringPiece::size_type StringPiece::copy(char* buf, size_type n,
79 size_type pos) const {
80 size_type ret = std::min(length_ - pos, n);
81 memcpy(dest: buf, src: ptr_ + pos, n: ret);
82 return ret;
83}
84
85bool StringPiece::contains(StringPiece s) const {
86 return find(s, pos: 0) != npos;
87}
88
89StringPiece::size_type StringPiece::find(StringPiece s, size_type pos) const {
90 if (length_ <= 0 || pos > static_cast<size_type>(length_)) {
91 if (length_ == 0 && pos == 0 && s.length_ == 0) return 0;
92 return npos;
93 }
94 const char *result = std::search(first1: ptr_ + pos, last1: ptr_ + length_,
95 first2: s.ptr_, last2: s.ptr_ + s.length_);
96 return result == ptr_ + length_ ? npos : result - ptr_;
97}
98
99StringPiece::size_type StringPiece::find(char c, size_type pos) const {
100 if (length_ <= 0 || pos >= static_cast<size_type>(length_)) {
101 return npos;
102 }
103 const char* result = static_cast<const char*>(
104 memchr(s: ptr_ + pos, c: c, n: length_ - pos));
105 return result != nullptr ? result - ptr_ : npos;
106}
107
108StringPiece::size_type StringPiece::rfind(StringPiece s, size_type pos) const {
109 if (length_ < s.length_) return npos;
110 const size_t ulen = length_;
111 if (s.length_ == 0) return std::min(ulen, pos);
112
113 const char* last = ptr_ + std::min(ulen - s.length_, pos) + s.length_;
114 const char* result = std::find_end(first1: ptr_, last1: last, first2: s.ptr_, last2: s.ptr_ + s.length_);
115 return result != last ? result - ptr_ : npos;
116}
117
118// Search range is [0..pos] inclusive. If pos == npos, search everything.
119StringPiece::size_type StringPiece::rfind(char c, size_type pos) const {
120 // Note: memrchr() is not available on Windows.
121 if (empty()) return npos;
122 for (size_type i = std::min(pos, length_ - 1);; --i) {
123 if (ptr_[i] == c) {
124 return i;
125 }
126 if (i == 0) break;
127 }
128 return npos;
129}
130
131// For each character in characters_wanted, sets the index corresponding
132// to the ASCII code of that character to 1 in table. This is used by
133// the find_.*_of methods below to tell whether or not a character is in
134// the lookup table in constant time.
135// The argument `table' must be an array that is large enough to hold all
136// the possible values of an unsigned char. Thus it should be be declared
137// as follows:
138// bool table[UCHAR_MAX + 1]
139static inline void BuildLookupTable(StringPiece characters_wanted,
140 bool* table) {
141 const StringPiece::size_type length = characters_wanted.length();
142 const char* const data = characters_wanted.data();
143 for (StringPiece::size_type i = 0; i < length; ++i) {
144 table[static_cast<unsigned char>(data[i])] = true;
145 }
146}
147
148StringPiece::size_type StringPiece::find_first_of(StringPiece s,
149 size_type pos) const {
150 if (empty() || s.empty()) {
151 return npos;
152 }
153 // Avoid the cost of BuildLookupTable() for a single-character search.
154 if (s.length_ == 1) return find_first_of(c: s.ptr_[0], pos);
155
156 bool lookup[UCHAR_MAX + 1] = { false };
157 BuildLookupTable(characters_wanted: s, table: lookup);
158 for (size_type i = pos; i < length_; ++i) {
159 if (lookup[static_cast<unsigned char>(ptr_[i])]) {
160 return i;
161 }
162 }
163 return npos;
164}
165
166StringPiece::size_type StringPiece::find_first_not_of(StringPiece s,
167 size_type pos) const {
168 if (empty()) return npos;
169 if (s.empty()) return 0;
170 // Avoid the cost of BuildLookupTable() for a single-character search.
171 if (s.length_ == 1) return find_first_not_of(c: s.ptr_[0], pos);
172
173 bool lookup[UCHAR_MAX + 1] = { false };
174 BuildLookupTable(characters_wanted: s, table: lookup);
175 for (size_type i = pos; i < length_; ++i) {
176 if (!lookup[static_cast<unsigned char>(ptr_[i])]) {
177 return i;
178 }
179 }
180 return npos;
181}
182
183StringPiece::size_type StringPiece::find_first_not_of(char c,
184 size_type pos) const {
185 if (empty()) return npos;
186
187 for (; pos < static_cast<size_type>(length_); ++pos) {
188 if (ptr_[pos] != c) {
189 return pos;
190 }
191 }
192 return npos;
193}
194
195StringPiece::size_type StringPiece::find_last_of(StringPiece s,
196 size_type pos) const {
197 if (empty() || s.empty()) return npos;
198 // Avoid the cost of BuildLookupTable() for a single-character search.
199 if (s.length_ == 1) return find_last_of(c: s.ptr_[0], pos);
200
201 bool lookup[UCHAR_MAX + 1] = { false };
202 BuildLookupTable(characters_wanted: s, table: lookup);
203 for (size_type i = std::min(pos, length_ - 1);; --i) {
204 if (lookup[static_cast<unsigned char>(ptr_[i])]) {
205 return i;
206 }
207 if (i == 0) break;
208 }
209 return npos;
210}
211
212StringPiece::size_type StringPiece::find_last_not_of(StringPiece s,
213 size_type pos) const {
214 if (empty()) return npos;
215
216 size_type i = std::min(pos, length() - 1);
217 if (s.empty()) return i;
218
219 // Avoid the cost of BuildLookupTable() for a single-character search.
220 if (s.length_ == 1) return find_last_not_of(c: s.ptr_[0], pos);
221
222 bool lookup[UCHAR_MAX + 1] = { false };
223 BuildLookupTable(characters_wanted: s, table: lookup);
224 for (;; --i) {
225 if (!lookup[static_cast<unsigned char>(ptr_[i])]) {
226 return i;
227 }
228 if (i == 0) break;
229 }
230 return npos;
231}
232
233StringPiece::size_type StringPiece::find_last_not_of(char c,
234 size_type pos) const {
235 if (empty()) return npos;
236 size_type i = std::min(pos, length_ - 1);
237 for (;; --i) {
238 if (ptr_[i] != c) {
239 return i;
240 }
241 if (i == 0) break;
242 }
243 return npos;
244}
245
246StringPiece StringPiece::substr(size_type pos, size_type n) const {
247 if (pos > length()) pos = length();
248 if (n > length_ - pos) n = length() - pos;
249 return StringPiece(ptr_ + pos, n);
250}
251
252const StringPiece::size_type StringPiece::npos = size_type(-1);
253
254} // namespace stringpiece_internal
255} // namespace protobuf
256} // namespace google
257